The purpose of this investigation is to study sensory perception in post menopausal women before and during hormone replacement therapy. A double blind, clinical trial approach will be used to compare the effects of low dose estrogen, progestin and placebo. 100 to 120 women will be evaluated. Two-point discrimination and vibration sensitivity will be measured as indicators of touch perception. Basic mechanisms through which ovarian hormones may influence peripheral sensory nerve function will be studied by laser Doppler measurement of blood flow in the skin microcirculation and electron-microscopic examination of skin tissue before and after treatment. The significance of change in sensory perception in relation to everyday functioning at home and in the work place will be measured. The research is to be done by a multidisciplinary team drawn from gynecology, experimental psychology, epidemiology, dermatology and psychiatry. This study holds the promise of defining and clarifying neurological signs and symptoms which are due to hormonal changes at menopause, investigating basic mechanisms of interaction between ovarian hormones and peripheral nerve and peripheral vascular function, and evaluating treatment approaches which, through their positive effects on sensory perception, enhance the functional capacity of women after menopause.